HUMAN PEDIGREES 27 



and the other has one son and three daughters. These 

 six children have not been seen by my correspondent. 



The Deductions from the Pedigree and General 

 Observations. 



There is one fact which I think needs particular 

 notice here. In considering this pedigree, we are 

 bound of course to face certain possibilities. Many 

 Europeans were resident in the island. But it needs 

 only the most casual glance at the photograph to 

 render it at once clear that the likeness between the 

 three sisters is very pronounced. There can be not 

 the slightest doubt, I think, that they are sisters by 

 the same parents. I have shown the photographs 

 to several friends and they concur in my belief. 

 Of course the resemblance is much greater between 

 the two white sisters than between them and the 

 coloured one. But even between them there 

 is, in the form of the eyelids and the eyebrows, a 

 strong suggestion of sisterhood. 



If this were a Mendelian phenomenon of the 

 simplest order, such as Professor Pearson has imagined 

 possible, we should expect that the offspring of such 

 parents would be in equal numbers " whites " and 

 coloured persons. There are actually 2 " whites " : 

 3 coloured persons plus two of unknown type. 

 But it is clear that this is not a simple type of 

 Mendelian phenomenon, because the coloured children 

 are not alike in respect of skin colour or hair characters, 

 and they are not exactly like their father. It 

 is clearly a more complex type of Mendelian 



